Federal immigration officers have arrested 54 people in New York in recent months as part of a crackdown on the Dominican American Trinitarios gang, U.S. Department of Homeland Security Secretary Kristi Noem said in Manhattan on Thursday.

The "Operation Salvo" arrests followed the shooting of an off-duty Customs and Border Protection officer in Upper Manhattan in July, allegedly by two individuals Noem said were affiliated with the Trinitarios. Miguel Mora Nunez, 21, and Christhian Aybar-Berroa, 22, were charged shortly after the July 19 shooting in Fort Washington Park, in which an unidentified CBP officer was seriously injured.

All of the 54 who were arrested were residing in the country without authorization and “loosely affiliated” to the Trinitarios, according to Frank Russo, CBP's director of field operations for New York. When pressed, Russo said the affiliations included "a spectrum from speaking to individuals associated with the gang to just having conversations."

Noem said “the vast majority” of those arrested had pending criminal charges or convictions, though she did not specify how many. Sixty percent of those who were arrested have since been deported, Noem said. The two charged in the shooting entered not guilty pleas.

Noem made the announcement at CBP's New York headquarters in One World Trade Center, where she was flanked by mugshots of men she said had been arrested as part of “Operation Salvo.” Her appearance came amid a firestorm over the fatal shooting of a U.S. citizen on Wednesday in Minneapolis by a federal officer deployed as part of President Donald Trump's immigration crackdown.

Noem defended the shooting of motorist Renee Nicole Good, 37, a mother of three.

Noem said the officer, later identified by multiple news organizations as Jonathan Ross, who opened fire was “following his training” and was “surrounded and assaulted and locked in by protesters.”

Democrats and other critics have condemned Noem and Trump's accounts of the shooting, saying they are contradicted by multiple videos that captured the violence. A New York Times video analysis shows that Good appeared to be turning away from the officer when he opened fire.

Minneapolis Mayor Jacob Frey called the federal accounts of the shooting “bulls---.” Minnesota Gov. Tim Walz posted "don't believe this propaganda machine" on X and urged residents to protest peacefully.

Noem also rebuked Mamdani, who characterized the shooting death as murder and said in a social media post on Wednesday afternoon that he stands with immigrants. Noem said the mayor “chose to stand with illegals instead of those individuals who just want the chance to raise their families in New York City.”

She and other officials also criticized New York’s “sanctuary city” policies, which limit city police and jail officers’ cooperation with federal immigration enforcement.

“We are here today because of the abject failure of the New York City bail reform laws and sanctuary city policies,” said ICE's New York Field Director Kenneth Genalo, who added that the two men who shot the CBP officer in July had previously been in NYPD custody.

In an interview with NPR on Thursday evening, Mamdani defended his commitment to the city’s sanctuary policies. He added that he told the president that ICE raids are “cruel,” “inhumane,” and don’t help public safety.

“My responsibility as the mayor of this city is to protect each and every New Yorker and to make sure we are following the law,” Mamdani said. “Here in New York City, we have sanctuary city policies that explicitly lay out what that looks like, and that is something that my administration is not going to take as guidance but as requirements."

Noem noted that while the president's discussions with Mamdani had been “productive,” her agency’s discussions with the new mayor and NYPD had “not been productive.” She declined to comment on whether there would be a surge in ICE enforcement in New York City.

Noem’s remarks drew criticism from immigrant rights activists and others.

“Your agency is dangerous, cruel, inept, and lawless, and has no place on our streets,” New York Civil Liberties Union Director Donna Lieberman said in a statement. “Contrary to your spin, the facts are that New York’s long-standing, bipartisan sanctuary laws have made our city safer, fueled our economy, strengthened our communities, and made it easier for people to access vital services that support public safety.”

This story has been updated with additional comment from Mayor Zohran Mamdani and others.